<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8" />
		<title>理想视口标准</title>
		<meta name="viewport" content="width=device-width"/>
		<style>
			*{
				padding: 0;
				margin: 0;
			}
			#d0{
				width: 375px;
				height: 300px;
				font-size: 20px;
				background-color: skyblue;
			}
		</style>
	</head>
	<body>
		<div id="d0">布局视口宽度为：</div>

		<script type="text/javascript" >
			const  d0= document.getElementById('d0')
			d0.innerHTML += document.documentElement.clientWidth

			console.log('该设备的布局视口宽度为：',document.documentElement.clientWidth)
		</script>
	</body>
</html>